Conventionally, a mobile phone, which is a typical example of a mobile information apparatus, notifies the user about an incoming call or mail by sounding a ringtone. However, a ringtone may be annoying to other people especially in a movie theater, on a train, and during a meeting. Further, while the user is driving, a ringtone may become a source of driver inattention, which results in the risk of a car accident. In order to address the problems noted above, mobile phones are provided with the function of manner modes, which may be referred to also as silent modes. For a manner mode, various settings are made in advance regarding the ringtone volume level and the vibration level of the vibrator. The user can place the mobile phone into a manner mode by operating a predetermined key. Usually, the user is required to operate keys each time to place the mobile phone into a manner mode. In order to reduce the user's trouble of making such key operations, a technique is suggest to automatically switch the mobile phone to a manner mode according to the user's schedule (See Patent Document 1, for example).    [Patent Document 1] JP 2001-189774-A